Common mode choke coil

Abstract

A common mode choke coil includes two laminated coil conductors, a first magnetic substrate arranged on one of the coil conductors, and a second magnetic substrate arranged on the other coil conductor. When it is assumed that a distance from a conductor center of the one coil conductor to the surface of the first magnetic substrate is designated as A, a distance from a conductor center of the other coil conductor to the surface of the second magnetic substrate is designated as B, and a distance from the conductor center of the one coil conductor to the conductor center of the other coil conductor is designated as C, C<(A+B)/2 is satisfied. Accordingly, because a difference in the distances between the magnetic substrates and the coil conductors becomes relatively small, a leakage inductance due to the difference in the distance decreases, and the cut-off frequency with respect to a differential mode signal can be increased.

What is claimed is: 
     
       1. A common mode choke coil comprising:
 first and second laminated coil conductors; 
 a first magnetic substrate arranged on the first coil conductor side; and 
 a second magnetic substrate arranged on the second coil conductor side, 
 wherein C<(A+B)/2 is satisfied where a distance from a conductor center of the first coil conductor to a surface of the first magnetic substrate is designated as A, a distance from a conductor center of the second coil conductor to a surface of the second magnetic substrate is designated as B, and a distance from the conductor center of the first coil conductor to the conductor center of the second coil conductor is designated as C. 
 
     
     
       2. The common mode choke coil as claimed in  claim 1 , wherein (A+B)/3<C<(A+B)/2 is satisfied. 
     
     
       3. The common mode choke coil as claimed in  claim 1 , wherein E<(D/3) is satisfied where a thickness of the first and second coil conductors is designated as E. 
     
     
       4. The common mode choke coil as claimed in  claim 1 , wherein A<B/3 is satisfied. 
     
     
       5. The common mode choke coil as claimed in  claim 1 , wherein a planar shape of the first and second coil conductors is a curved spiral pattern.